JBW030-Series Power Module: dc-dc Converters
36-75 Vdc Input; 3.3 Vdc and 5 Vdc Outputs; 30 W
Data Sheet
March 27, 2008
Output Voltage Set-Point Adjustment
(Trim)
Feature Descriptions (continued)
Remote On/Off (continued)
Output voltage trim allows the user to increase or
decrease the output voltage set point of a module. This
is accomplished by connecting an external resistor
between the TRIM pin and either the SENSE(+) or
SENSE(–) pins. With an external resistor between the
TRIM and SENSE(–) pins (Radj-down), the output voltage
set point (VO, adj) decreases (see Figure 16). The fol-
VI(+)
VI(-)
–
Von/off
SENSE(+)
VO(+)
+
lowing equation determines the required external-resis-
tor value to obtain an output voltage change of % Δ.
LOAD
REMOTE
ON/OFF
VO(–)
Ion/off
SENSE(–)
1 – %Δ
%Δ
⎛
⎝
⎞
⎠
------------------
Radj-down =
10 kΩ
For example, to lower the output voltage by 20%, the
external resistor value must be:
8-720(C).h
1 – 0.2
0.2
⎛
⎝
⎞
⎠
Figure 14. Remote On/Off Implementation
-----------------
Radj-down =
10 kΩ = 40.00 kΩ
With an external resistor connected between the TRIM
and SENSE(+) pins (Radj-up), the output voltage set
point (VO, adj) increases (see Figure 17). The following
equations determine the required external-resistor
value to obtain an output voltage change of % Δ.
Remote Sense
Remote sense minimizes the effects of distribution
losses by regulating the voltage at the remote-sense
connections. The voltage between the remote-sense
pins and the output terminals must not exceed the out-
put voltage sense range given in the Feature Specifica-
tions table, i.e.:
JBW030A:
1 + %Δ
%Δ
VO, nom
2.5
⎛
⎞ ⎛
⎠ ⎝
⎞
⎠
------------------
Radj-up = ----------------- – 1
10 kΩ
⎝
[VO(+) – VO(–)] – [SENSE(+) – SENSE(–)] ≤ 0.2 V
For example, to increase the output voltage of the
JBW030A by 5%, the external resistor value must be:
The voltage between the VO(+) and VO(–) terminals
must not exceed the minimum output overvoltage shut-
down voltage as indicated in the Feature Specifications
table. This limit includes any increase in voltage due to
remote-sense compensation and output voltage set-
point adjustment (trim). See Figure 15.
1 + 0.05
--------------------
5.0
2.5
⎛
⎞ ⎛
⎠ ⎝
⎞
⎠
Radj-up = ------- – 1
10 kΩ = 210 kΩ
⎝
0.05
JBW030F:
If not using the remote-sense feature to regulate the
output at the point of load, then connect SENSE(+) to
VO(+) and SENSE(–) to VO(–) at the module.
1 + %Δ
%Δ
VO, nom
1.235
⎛
⎞ ⎛
⎠ ⎝
⎞
⎠
------------------
Radj-up = ------------------- – 1
10 kΩ
⎝
For example, to increase the output voltage of the
JBW030F by 5%, the external resistor must be:
SENSE(+)
SENSE(–)
1 + 0.05
--------------------
3.3
1.235
⎛
⎞ ⎛
⎠ ⎝
⎞
⎠
Radj-up = -------------- – 1
10 kΩ = 351.1 kΩ
⎝
0.05
VI(+)
VI(-)
VO(+)
VO(–)
IO
SUPPLY
LOAD
II
CONTACT
RESISTANCE
CONTACT AND
DISTRIBUTION LOSSES
8-651(C).m
Figure 15. Effective Circuit Configuration for
Single-Module Remote-Sense Operation
Lineage Power
9
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
